I know it all but screams that the film is set in the Alien universe. However, I think Scott would be better served by saying something along the lines of "Well, it looks like it could be in the same universe but we aren't saying it is. If you as the viewer want it to be a prequel, so be it. If not, it works well enough on its own."

A site called Geektyrant has a spoilerish synopsis that the trailer sort of validates. It is a prequel, this is set in the time before Alien takes place. There are apparently no Xenomorphs in this film, but we will meet other, important entities. As you might have guessed, it has to do with the origins of life, and mankind itself.

Also, cool that Fassbender is in this film, playing the android David. I've read a bit about his storyline and if that comes true, I like it.

I think most who've seen the movies know what that crescent ship is and in some of the comics you see what was inside it and what they represent (see how non-spoilery that was ) so I think it has to be seen as a prequel. Also, looks awesome.

Eh. I was kinda' sad to learn it was an Alien prequell... I was genuinely looking forward to something new and exciting. For the first time in a long time, a trailer had made me excited, but it's just another cash cow.

Plus, it had quite a different aestetic to Alien. I'm thinking first three Star Wars 'in the past' wot mode. xD